A typical piston-and-cylinder type motor generally includes a plurality of pistons/cylinders in one or more rows and including a cylinder head assembly. The cylinder head assembly includes a piston rod and at least one valve for each piston/cylinder, operatively associated with a respective rocker arm. A stud projects through each rocker arm, and an adjusting nut is threaded onto each stud for adjusting the position of the rocker arm.
Typically, an elongated valve cover encloses the cylinder head assembly and is secured to the cylinder head most commonly by one of two arrangements. First, the cover is provided with a peripheral flange or lip, and the cover is secured directly to the cylinder head by bolts or other fasteners extending through the peripheral flange. In some vehicles, the peripheral flange seats on top of a narrow rib projecting upwardly from the cylinder head, and the flange cannot be used to fasten the cover to the head, because the rib is too narrow for receiving the bolts or fasteners. In those instances, a second fastening system is used whereby bolts or studs project upwardly from the cylinder head between adjacent cylinders and through a top wall of the cover to, thereby, fasten the cover to the cylinder head.
In some engines or motors, a stud girdle is used to interlock the adjusting nuts for the rocker arms. A typical stud girdle is a two-part structure which is elongated and is used to clamp the adjusting nuts therebetween. The stud girdle locks all of the adjusting nuts together, prevents the nuts from rotating and also prevents an individual stud (to which the adjusting nuts are secured) from bending because all of the nuts are "unitized" by the stud girdle. Some engines or motors, including the engine blocks and cylinder heads, are fabricating of aluminum or an aluminum alloy material which can expand and contract considerably in response to heat variances. This can cause one or more of the adjusting nuts to become loose which, in turn, results in lost horsepower for the motor. The stud girdle locks the adjusting nuts and prevents such losses.
Unfortunately, when using a stud girdle, and when the valve cover cannot be secured to the cylinder head by means of the peripheral flange of the cover, there is no way to secure the cover to the cylinder head because the stud girdle forms a barrier for any bolts to extend upwardly from the cylinder head to the top wall of the cover. Consequently, in those types of engines, the use of a stud girdle is prevented and the considerable advantages thereof cannot be utilized.
The present is directed to solving these problems by providing a valve cover system in which the valve cover is mounted directly to the stud girdle.